If you are someone who looks outwards for the cures to your anxiety, grumpy mood, weak immune system and stagnant weight then perhaps it is time to look inwards and get to the guts of the problem - literally. There has been a lot of hoo ha lately about the bacteria in our guts being the unsung heroes of what keeps us looking and feeling good so I thought it was about time to explore what's actually going on down there.
You have trillions of bacteria alive and kicking in your gastrointestinal tract (namely your small and large intestine). Study after study is showing us that they can influence our mental and physical health. The two buzz terms you would have heard are pre and probiotics, both are necessary for a healthy gut environment but have different responsibilities.
Pre vs Probiotics
Probiotics are the ‘good’ bacteria that are already alive. (Think about the little blue men on the inner health plus add). They are delivered in their active form into your gut through food or supplements.
1. Fermented vegetables (sauerkraut, kimchi (see below), dill pickles, miso paste)
2. Kefir - fermented milk
3. Yoghurt - (with added natural cultures)
4. Kombucha - fermented drink (watch the sugar)
5. Supplements – eg. Yakult, Inner Health Plus or Metagenics which is also dairy free, suitable for those who are lactose free
Prebiotics are best thought of as the food for probiotics. These are non-digested carbohydrates like the fibre from fruit, vegetables and grains that the good bacteria feed off to grow and multiply. Making sure you have enough fibrous foods in your diet ensures you have enough food for your probiotics to live off.
- Vegetables especially asparagus, artichoke, leeks, shallots, snow peas, cabbage and sweet corn.
- Legumes: chickpeas, lentils, kidney beans, baked beans, soy beans
- Fruit (bananas, peaches, persimmons, pomegranate, dried fruit without added sugar, watermelon)
- Wholegrain products (rolled oats, barley, rye products, wheat bran, pasta, wholegrain breads, quinoa)
- Nuts (cashews, pistachios)
What do they do?
Controls appetite (weight watchers read on): certain strains of good bacteria like helicobacter pylori dampen down the signal from ghrelin, a hormone that increases hunger. So just modifying or adding some probiotics to your diet may help you to curb the munchies or from devouring the entire large pizza.
Immunity: the good bacteria in your gut keep the number of harmful pathogens (disease causing cells) down. If your balance is tipped in the favour of the ‘bad’ bacteria that is when you are more likely fall ill. This is especially important if you have recently taken a course of ‘antibiotics’ as the medication has wiped out the numbers of bacteria in your gut to rid you of the infection you caught. Unfortunately this means that a lot of the good bacteria have also been lost.
Stress & anxiety: Notice that when you are stressed/ anxious that you have gut issues like discomfort, bloating, and constipation/diarrhea? Well you are not alone! More and more research is revealing the powerful relationship between the brain and gut. A recent study into the effect of prebiotics on decreasing anxiety was one of the first trials conducted in humans that showed those who took prebiotic supplements had less anxiety when confronted with negative stimuli (1). They also showed that prebiotic consumers had lower cortisol levels in their saliva when they woke in the morning. Cortisol is a hormone released by the body when its stressed and anxiety. One of the authors of the study Dr Kristen Tillisch summarized it nicely saying that ‘the relationship between the gut and brain is a two way street’.
Mood enhancers: our digestive systems are connected to our brain. The bacteria in your gut actually make chemical signals (neurotransmitters) that are sent to the brain, which in turn function to control your mood. Two psychologists recently published an article in Brain, Behaviour and Immunity journal that showed intake of probiotics may help reduce negative thoughts associated with sad mood (2). This not only means that you could improve your daily mood (goodbye grumpy, irritable negative Nancy!) but could prove an additional prevention or treatment for those with depression.
As we can see the science and evidence is still emerging about the complete role of pre and probiotics in the diet, but it all seems to be pointing to the fact that we should be taking more care of our gut health by increasing our intakes of foods rich in pre and probiotics. Make sure to call an accredited practicing dietitian if you’d like advice on how best to do this in your life!